Casting Double to Integer

Question

I am running into a casting issue. I cannot seem to figure out the problem since everything appears to be in order. I understand that to explicitly cast from the Double wrapper class to the Integer wrapper class it can be done however, my compiler does not recognize it. Am I missing something obvious?

The exact error I'm getting is : "Inconvertible types; cannot cast 'double' to 'java.lang.Integer'.

Thanks for your help!

private HashMap<String, Integer> shortestPath(String currentVertex, Set<String> visited) {
        double tempVal = Double.POSITIVE_INFINITY;
        String lowestVertex = "";

        Map<String, Integer> adjacentVertex = this.getAdjacentVertices(currentVertex);
        HashMap<String, Integer> lowestCost = new HashMap<String, Integer>();

        for(String adjacentNames : adjacentVertex.keySet()) {
            Integer vertexCost = adjacencyMap.get(currentVertex).get(adjacentNames);
            if(!visited.contains(adjacentNames) && (vertexCost < tempVal)) {
                lowestVertex = adjacentNames;
                tempVal = vertexCost;
            }
        }
        lowestCost.put(lowestVertex, (Integer)tempVal);

        return lowestCost; 
    }

possible duplicate of [How to convert Double to int directly?](http://stackoverflow.com/questions/5404149/how-to-convert-double-to-int-directly) — David Brossard, Aug 06 '14 at 11:35
@DavidBrossard no it is not. OP wants to Casting double to Integer — Ruchira Gayan Ranaweera, Aug 06 '14 at 11:36
Why have `tempVal` declared as a double when it appears that you always want an int? — Brett Okken, Aug 06 '14 at 11:40
tempVal had to be declared as a double rather than an int because of the Positive_Infinity value. All I had to do was change double tempVal to Double tempVal. — ButtahNBred, Aug 06 '14 at 11:42

score 4 · Accepted Answer · edited May 23 '17 at 12:15

4

You cannot cast directly from Double to Integer. You need to do the following:

Double d = new Double(1.23);
int i = d.intValue();

as suggested in How to convert Double to int directly?

edited May 23 '17 at 12:15

Community

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answered Aug 06 '14 at 11:36

David Brossard

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OP wants to Casting double to Integer – Ruchira Gayan Ranaweera Aug 06 '14 at 11:37
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@RuchiraGayanRanaweera and what does the above code do? – A4L Aug 06 '14 at 11:38
OP want `Integer` not `int` – Ruchira Gayan Ranaweera Aug 06 '14 at 11:40
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@RuchiraGayanRanaweera `Integer` and `int` autobox just fine, so where is the problem? – A4L Aug 06 '14 at 11:42
That segment of code is called by another function to find the shortest path for Dijkstras algorithm. – ButtahNBred Aug 06 '14 at 11:43
It would work, but it still creates an extra Double instance every time it's called (not speaking of the extra code :)). – david a. Aug 06 '14 at 11:53

score 0 · Answer 2 · answered Aug 06 '14 at 11:41

0

Try this

 lowestCost.put(lowestVertex, (Integer) new Double(tempVal).intValue());

Hope it will resolve your issue

answered Aug 06 '14 at 11:41

prashant thakre

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score 0 · Answer 3 · answered Aug 06 '14 at 11:43

This seems to be the easiest:

lowestCost.put(lowestVertex, (int) tempVal);

First, explicitely cast to an int, then have the compiler to autobox the int value to an Integer.

Note that this also eliminates the need to create various helper throwaway objects that other answers suggest (an extra Double or even a String). It is the most efficient way I can think of (at this moment).

Casting Double to Integer

3 Answers3